Gearbox



FIG. 1 is a perspective view showing the ornamental design of a gearbox in accordance with the present invention;

FIG. 2 is a side view of the embodiment of FIG. 1;

FIG. 3 is a front view of the embodiment of FIG. 1; and,

FIG. 4 is a back view of the embodiment of FIG. 1.

The broken lines in the drawings depict unclaimed environmental subject matter. 

CLAIM The ornamental design of gearbox, as shown. 